"Can I trust the readers?" - I don't know, what is it that you are suspicious of, and how can you be certain it won't happen?
Look. It's going to get re-written. It's going to get revised. That's the process. Art is never completed - only abandoned. Glad you think it's perfect - all you have to do is find the perfect home for it.
How does that work? You keep submitting it until you find someone who likes it EXACTLY THE WAY IT IS. That means, if someone says "Well, it's almost there - can we change the main character to female? Because I think I have an actress that is perfect for the part ... and we keep the female romance, give it a GLBT twist..." You're happy to say "Keep the money, this is perfect the way it is."
If you think it's flawless - and won't need to be revised to meet a filmmaker's needs and requirements - then you should make it.
IN which case - you've got all the skills necessary to do that right?
"Work out all my options" - should include rewriting it to meet a potential buyer's needs.
http://gointothestory.blcklst.com/2013/01/20-great-writers-on-the-art-of-revision.html
I'm not saying it's not ready to go out. It might be at a place where you can't think of it needing a change. Frequently, I finish a script and think to myself - "You know, I could make this ending more "Hollywood" or more "Art House" ... And I put those alternate endings in my pocket - for when someone asks.
There is a Share Your Work forum on this board you could post there. You could ask to 'exchange' scripts with someone - offer to read and critique theirs, in exchange for same.
I typically get at least six, preferably a dozen readers for my scripts or novels. Now then, if more than TWO people, say the same thing about an issue - I'll take a serious look at what that might be. "I don't understand how they got from here to here... I don't know why they just don't call the police... Her actions here, are completely unbelievable, we had no idea up to this point, that she was a weapons expert, and you never explain how she got that training..." Whatever. If two or three people have the same issue with the character, the dialog, the plot point - I definitely take a hard look at it. Sure, some people just won't like a character. "I didn't like the guy..." And someone else "LOVES" him... that's just personal preference. And when I get conflicting feedback - THAT'S useful too. Is it MEN who like/don't like it? Is it just the older readers? Maybe it's a target audience issue - important to know and understand come marketing time.
Register it with the WGA. If you think it's 'perfect' just the way it is - go ahead and file with the copyright office - cause the WGA registration is only good for five years anyway.
Get feedback - lots of it. LISTEN to it. Keep rewriting it. (Hell, sometimes history overtakes our plots, technology changes, politics change - scripts need to be revised to keep them current.)
Then start writing your next one.